AP Environmental Science Flashcards: K-Selected r-Selected Species
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Review key ideas with interactive flashcards. This set includes 11 cards to help you master important concepts.
What are K-selected species?
K-selected species are organisms that tend to be large, have few offspring, live in stable environments, have long life spans, and reproduce more than once.
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What are K-selected species?
K-selected species are organisms that tend to be large, have few offspring, live in stable environments, have long life spans, and reproduce more than once.
What are r-selected species?
r-selected species are organisms that tend to be small, have many offspring, mature early, have short life spans, and may reproduce only once.
Which reproductive strategy is characterized by early maturation and a short lifespan?
The r-selected strategy is characterized by species that mature early and have short life spans.
Why are K-selected species, like elephants or whales, often more vulnerable to invasive species than r-selected species?
K-selected species are typically more adversely affected by invasive species because their low reproductive rates make it difficult for their populations to recover from the increased competition.
Which reproductive strategy is associated with stable environments and multiple reproductive events?
The K-selected strategy is associated with stable environments and species that reproduce more than once in their lifetime.
How does the level of competition differ between the environments of K-selected and r-selected species?
Competition is usually relatively high for K-selected species living in stable environments, whereas it is typically low for r-selected species.
List two key differences between K-selected and r-selected species based on their typical size and reproductive frequency.
K-selected species tend to be large and reproduce more than once, while r-selected species tend to be small and may reproduce only once.
Define biotic potential.
Biotic potential refers to the maximum reproductive rate of a population in ideal conditions, without any limiting factors.
Contrast the number of offspring and lifespan between K-selected and r-selected species.
K-selected species typically have few offspring and long life spans, while r-selected species have many offspring and short life spans.
A species of mouse is small, matures in a few weeks, and can produce a large litter of offspring. Is it likely K-selected or r-selected?
This species is likely r-selected, as its characteristics (small size, early maturation, many offspring) align with the r-selected strategy.
What reproductive strategy do most invasive species exhibit?
Most invasive species are r-selected species, which allows them to reproduce and spread rapidly in new environments.